1. Field of the Invention
The field of art to which this invention pertains includes overhead safety guards for industrial vehicles.
2. Description of the Prior Art
It is standard practice to equip industrial lift trucks and other industrial vehicles with overhead guards to protect the operator. The overhead guard commonly includes a canopy extending over the operator's compartment of the industrial vehicle.
Industrial vehicles are often employed in situations where a vehicle of minimum width and maximum maneuverability is desired. One example of this type of industrial vehicle is a narrow-aisle lift truck as shown in U.S. Pat. No. Des. 237,371, assigned to the Assignee of the present invention. Narrow-aisle lift trucks are designed for use in warehouse aisles where aisle width between stacking racks is desirably minimized. The stacking racks often employ horizontal members for supporting pallets. The horizontal members are positioned at various vertical heights. It is common to provide the supporting members at vertical heights which are parallel to the back or head of the operator when he is driving the lift truck. The canopy of the overhead guard of a narrow-aisle lift truck is commonly attached to and supported by the upright of the lift truck.
Narrow-aisle lift trucks manufactured and sold by the Assignee of the present invention optionally include a pair of rear vertical posts extending between the respective rear ends of the canopy and the respective tops of the spaced-apart service compartments which are located at the rear end of the lift truck body. The rear posts are straight elongated beams which are secured at both ends to the lift truck by nut and bolt assemblies. The use of the rear vertical posts hinders operator entrance and egress into the vehicle and obscures operator visibility. Also, the rear vertical posts have to be detached from the tops of respective service compartments before the compartment doors can be opened for servicing the components contained therein. Additionally, if the rear vertical posts are spaced far enough apart to not obscure operator visibility, it is quite possible that the distance between the posts will be greater than the clearance between pallet supporting members making drive-in operations between stacking racks impossible.
However, the use of conventional rear vertical posts on narrow-aisle lift trucks does provide some advantages. Commonly loads are removed from vertical rack openings by backing up while turning abruptly to the side. In this operation the operator is usually sitting or standing at the rear of the truck and is facing forward or to the side of the truck away from the direction of rearward truck travel. Operator error during backing or turning can cause the lift truck to back into pallets or racking on the opposite side of the aisle with possible injury to the truck operator. The provision of the conventional rear vertical posts protects the operator from direct initial contact with the rack or pallets during such a collision.